Big data is everywhere. As evaluators, often our task is to transform data into information that answers questions and guides better decision-making. However, existing data is often collected for a myriad of purposes, siloed in separate agencies, and protected by different privacy laws. The purpose of these materials is to improve researchers’ ability to construct high-quality longitudinal, cross-agency datasets to answer policy and research questions. The materials suggest strategies for obtaining and securing personally identifiable information, merging datasets without common identifiers, and overcoming common data quality issues with longitudinal datasets.#HowTo #MatchingData #DataSecurity #bigdata #CleaningData